In-process quality sampling with sub-lots

How in-process quality sampling with sub-lots works in FactoryLogix:

1. An operator initiates a Take a Sample activity.
   
   FactoryLogix identifies the specific production units to associate with the sampling activity. As a result, the AQL lot size for the sub-lot is established and the sample size is also established (based on the sampling plan and configured AQL levels).
   

2. Units are randomly chosen from the sub-lot and inspected until the sample size is met or the sub-lot fails.
   

• If the sub-lot passes, all units associated with the sub-lot are recorded as Passed at the sampled inspection operation and are permitted to proceed downstream.

• If the sub-lot fails, all units associated with the sub-lot are recorded as Failed and may be re-routed to an out-of-route operation or flow.
  

Note

If configured to do so, the system may force 100 percent inspection of an entire sub-lot or scrap the sub-lot automatically.

• (Optional) Any units produced at the Key Tracking Operation since the time that the sample was taken may also be included automatically as part of a Failed sub-lot and processed accordingly.

How to configure a process flow for sub-lot sampling

To use in-process quality sampling with sub-lots, you configure a process flow with two operations: Key Tracking and Sampled Inspection.

Key Tracking Operation

• This is the operation in the process flow from which sub-lots will be established.

• This must be an operation through which all production units are tracked.

• The Take a Sample activity typically takes place at the Key Tracking operation, but it is not required.

Sampled Inspection Operation

• This is the operation in a process flow where the inspection of sampled items will be performed.

• The operation will be configured as a Sampled Inspection operation and configured to inspect using sub-lots rather than the full batch.

• The operation must be at a point in the process flow after the related Key Tracking Operation.

Initiating the Take a Sample activity

You can add the Take a Sample activity to any step of an operation’s steps and activities.

• The operator can invoke the Take a Sample activity at any time (a unit doesn't need to be started in the Production environment).

• If sampling is to be done at a specific time interval, you specify the frequency at the step level.

• When the interval elapses, the activity is highlighted, indicating it is time for the Take a Sample activity to be performed.

Note

There is no way to force an operator to perform the sampled inspection at the appropriate time interval, but the activity will be highlighted—it is up to the operator to initiate the activity from the user interface.

All units completed at the Key Tracking Operation at the time when the Take a Sample activity was initiated and since the last time a sample was taken are automatically associated with the new sub-lot. 

Sampled inspection of sub-lots

Units in a sub-lot are inspected at a Sampled Inspection operation that is targeted in the configuration of the associated Take a Sample activity.

Initiate the sampled inspection

The operator initiates a sampled inspection by scanning one of the units previously associated with the sub-lot by the Take a Sample activity.  Based on that association, the appropriate sub-lot sample size, and number of remaining units needed to complete the sample is displayed to the operator in FactoryLogix.

The sampled inspection proceeds normally until the sub-lot passes or fails. If a sub-lot fails, all units in the sub-lot will be re-routed, scrapped, or 100% inspected (depending on your configuration).

How to handle non-serialized production units

• Non-serialized and hybrid process flows cannot start with a Sampled Inspection operation.

• The first tracked operation in a non-serialized or hybrid process flow must be non-sampling and cannot be part of an Any Order grouping or an Or grouping.

• With non-serialized batches, the system determines that quantity/units are active and introduced on the batch by reviewing the quantity (and any units serialized "on the fly") at the first operation.

Sub-lot sampled inspection

• In order for sub-lot based sampled inspection to function, all non-serialized production units are required to move through the Key Tracking and Sampled Inspection operations contained in serialized carriers. A single serialized carrier can contain any number of non-serialized production units that are traveling through the process together.

• Only non-serialized units contained in serialized carriers may be associated to sub-lots during the Take a Sample activity. Similarly, only non-serialized units contained within serialized carriers may be inspected during sub-lot based sampled inspection. 

• If a sub-lot fails, all non-serialized units associated with the sub-lot—and contained in the related carriers—will be processed (re-routed, scrapped, and so on) accordingly.

• If a sub-lot passes, you can configure the Sampled Inspection operation to unload all carriers related to the sub-lot automatically.